Disposable container covers capable of covering containers of various sizes and shapes have been in use for many years. Such covers typically include a plastic film, such as polyethylene, provided in sufficient dimension to overlie the container opening. The film then employs surface tension or elastic bands to secure the film to the container, such as with Saran® wrap or Quick Covers®, respectively, both being products of the present assignee, with the latter having an elastic band sewn directly to the film around its perimeter. The elastic band bordering the film is attached in such a manner that tension is created on the film, thereby creating a hollow enclosure with an expandable opening for placing atop and around containers of various sizes and shapes.
Use of such container covers is common for both perishable and nonperishable items. While these covers are beneficial in many respects, they are not without room for improvement. A common problem with existing container covers is the lack of an effective seal between the cover and the container. This is especially problematic with regard to food storage. First, depending on the size of the container cover relative to the container, the conventional container covers described above are vulnerable to slippage and inadvertent removal from the container. Any attempt at preserving freshness or protecting the contents of the container from exposure to various elements is futile where the container cover does not actually cover the container, but instead, slips off the container.
Even when such conventional covers remain appropriately positioned on a container, their sealing capabilities are limited. More specifically, given the limited constriction afforded by elastic bands, the susceptibility of films to lose surface tension, and/or the irregular shapes of the containers being sealed, air and moisture can flow relatively freely in and out of containers covered with conventional container covers. Consequently, where a substantial or hermetic seal is desired, as opposed to where air or moisture ventilation is desired, the goal of preserving the freshness of perishable items is less likely to be realized with conventional disposable covers.
An additional problem with conventional container covers relates to manufacturing. Specifically, conventional container covers, as described above, require the slow, labor intensive manufacturing step of manually sewing an elastic band to the periphery of the film. These covers do not readily lend themselves to high-speed automated manufacturing, in turn, driving up the cost and time of manufacturing conventional container covers.